You have to give some more material, maybe the original drawing file with the arrow, and the library file with the arrow only.
Perhaps you have done something wrong when creating the library file. You might try it again.
Sorry for the wrong information. I'd like to provide more details.
1, I create a arrow part. (Draw a triangle, then "hatch" it with solid.)
2, I save this arrow into library.
3, I want to create a arrow with line. I draw a line. Then insert the arrow created in step 1.
4, I save the arrow with line as one part into library.
5, I insert the arrow created in step 4 into a new paper. The line is OK. But the arrow is on wrong position.
But if I draw a line first. Then draw a triangle and "hatch" it with solid. Finally, save this as one part into library. When I insert this part, it's OK.
Maybe there is a bug of combining the parts from library as new part.